Exposure to indoor air pollution from solid fuel and its effect on depression: a systematic review and meta-analysis.

A growing body of research has investigated the relationship between indoor air pollution from solid fuel and depression risk. Our study aimed to elucidate the relationship between indoor air pollution from solid fuel and depression in observational studies. The effect of indoor air pollution on depression was estimated using pooled odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was evaluated by the I-squared value (I 2 ), and the random-effects model was adopted as the summary method. We finalized nine articles with 70,214 subjects. The results showed a statistically positive relationship between the use of household solid fuel and depression (OR = 1.22, 95% CI = 1.09-1.36). Subgroup analysis based on fuel type groups demonstrated that indoor air pollution from solid fuel was a higher risk to depression (OR = 1.24, 95% CI = 1. 10-1.39; I 2  = 67.0%) than that from biomass (OR = 1.18, 95% CI = 0.96-1.45; I 2  = 66.5%). In terms of fuel use, the use of solid fuel for cooking and heating increased depression risk, and the pooled ORs were 1.21 (95% CI = 1.08-1.36) and 1.23 (95% CI = 1.13-1.34). Exposure to indoor air pollution from solid fuel might increase depression risk.